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Scollo F, Evci H, Amaro M, Jurkiewicz P, Sykora J, Hof M. What Does Time-Dependent Fluorescence Shift (TDFS) in Biomembranes (and Proteins) Report on? Front Chem 2021; 9:738350. [PMID: 34778202 PMCID: PMC8586494 DOI: 10.3389/fchem.2021.738350] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/21/2021] [Indexed: 11/17/2022] Open
Abstract
The organization of biomolecules and bioassemblies is highly governed by the nature and extent of their interactions with water. These interactions are of high intricacy and a broad range of methods based on various principles have been introduced to characterize them. As these methods view the hydration phenomena differently (e.g., in terms of time and length scales), a detailed insight in each particular technique is to promote the overall understanding of the stunning “hydration world.” In this prospective mini-review we therefore critically examine time-dependent fluorescence shift (TDFS)—an experimental method with a high potential for studying the hydration in the biological systems. We demonstrate that TDFS is very useful especially for phospholipid bilayers for mapping the interfacial region formed by the hydrated lipid headgroups. TDFS, when properly applied, reports on the degree of hydration and mobility of the hydrated phospholipid segments in the close vicinity of the fluorophore embedded in the bilayer. Here, the interpretation of the recorded TDFS parameters are thoroughly discussed, also in the context of the findings obtained by other experimental techniques addressing the hydration phenomena (e.g., molecular dynamics simulations, NMR spectroscopy, scattering techniques, etc.). The differences in the interpretations of TDFS outputs between phospholipid biomembranes and proteins are also addressed. Additionally, prerequisites for the successful TDFS application are presented (i.e., the proper choice of fluorescence dye for TDFS studies, and TDFS instrumentation). Finally, the effects of ions and oxidized phospholipids on the bilayer organization and headgroup packing viewed from TDFS perspective are presented as application examples.
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Affiliation(s)
- Federica Scollo
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Hüseyin Evci
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Mariana Amaro
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Jan Sykora
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
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Moulton ER, Hirsche KJ, Hobbs ML, Schwab JM, Bailey EG, Bell JD. Examining the effects of cholesterol on model membranes at high temperatures: Laurdan and Patman see it differently. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1571-1579. [DOI: 10.1016/j.bbamem.2018.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/10/2018] [Accepted: 05/24/2018] [Indexed: 10/16/2022]
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The complex nature of calcium cation interactions with phospholipid bilayers. Sci Rep 2016; 6:38035. [PMID: 27905555 PMCID: PMC5131315 DOI: 10.1038/srep38035] [Citation(s) in RCA: 175] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 11/03/2016] [Indexed: 01/21/2023] Open
Abstract
Understanding interactions of calcium with lipid membranes at the molecular level is of great importance in light of their involvement in calcium signaling, association of proteins with cellular membranes, and membrane fusion. We quantify these interactions in detail by employing a combination of spectroscopic methods with atomistic molecular dynamics simulations. Namely, time-resolved fluorescent spectroscopy of lipid vesicles and vibrational sum frequency spectroscopy of lipid monolayers are used to characterize local binding sites of calcium in zwitterionic and anionic model lipid assemblies, while dynamic light scattering and zeta potential measurements are employed for macroscopic characterization of lipid vesicles in calcium-containing environments. To gain additional atomic-level information, the experiments are complemented by molecular simulations that utilize an accurate force field for calcium ions with scaled charges effectively accounting for electronic polarization effects. We demonstrate that lipid membranes have substantial calcium-binding capacity, with several types of binding sites present. Significantly, the binding mode depends on calcium concentration with important implications for calcium buffering, synaptic plasticity, and protein-membrane association.
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4
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Relationships between membrane water molecules and Patman equilibration kinetics at temperatures far above the phosphatidylcholine melting point. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:942-50. [DOI: 10.1016/j.bbamem.2014.12.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 12/18/2014] [Accepted: 12/24/2014] [Indexed: 11/18/2022]
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5
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Demchenko AP, Duportail G, Oncul S, Klymchenko AS, Mély Y. Introduction to fluorescence probing of biological membranes. Methods Mol Biol 2015; 1232:19-43. [PMID: 25331125 DOI: 10.1007/978-1-4939-1752-5_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Fluorescence is one of the most powerful and commonly used tools in biophysical studies of biomembrane structure and dynamics that can be applied on different levels, from lipid monolayers and bilayers to living cells, tissues, and whole animals. Successful application of this method relies on proper design of fluorescence probes with optimized photophysical properties. These probes are efficient for studying the microscopic analogs of viscosity, polarity, and hydration, as well as the molecular order, environment relaxation, and electrostatic potentials at the sites of their location. Being smaller than the membrane width they can sense the gradients of these parameters across the membrane. We present examples of novel dyes that achieve increased spatial resolution and information content of the probe responses. In this respect, multiparametric environment-sensitive probes feature considerable promise.
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Affiliation(s)
- Alexander P Demchenko
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, 9 Leontovicha Street, Kiev, 01030, Ukraine,
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6
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Bagatolli LA. Monitoring Membrane Hydration with 2-(Dimethylamino)-6-Acylnaphtalenes Fluorescent Probes. Subcell Biochem 2015; 71:105-125. [PMID: 26438263 DOI: 10.1007/978-3-319-19060-0_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A family of polarity sensitive fluorescent probes (2-(dimethylamino)-6-acylnaphtalenes, i.e. LAURDAN, PRODAN, ACDAN) was introduced by Gregorio Weber in 1979, with the aim to monitor solvent relaxation phenomena on protein matrices. In the following years, however, PRODAN and particularly LAURDAN, were used to study membrane lateral structure and associated dynamics. Once incorporated into membranes, the (nanosecond) fluorescent decay of these probes is strongly affected by changes in the local polarity and relaxation dynamics of restricted water molecules existing at the membrane/water interface. For instance, when glycerophospholipid containing membranes undertake a solid ordered (gel) to liquid disordered phase transition the fluorescence emission maximum of these probes shift ~ 50 nm with a significant change in their fluorescence lifetime. Furthermore, the fluorescence parameters of LAURDAN and PRODAN are exquisitely sensitive to cholesterol effects, allowing interpretations that correlate changes in membrane packing with membrane hydration. Different membrane model systems as well as innate biological membranes have been studied with this family of probes allowing interesting comparative studies. This chapter presents a short historical overview about these fluorescent reporters, discusses on different models proposed to explain their sensitivity to membrane hydration, and includes relevant examples from experiments performed in artificial and biological membranes.
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Affiliation(s)
- Luis A Bagatolli
- Membrane Biophysics and Biophotonics Group/MEMPHYS-Center for Biomembrane Physics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark.
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7
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The alteration of lipid bilayer dynamics by phloretin and 6-ketocholestanol. Chem Phys Lipids 2013; 178:38-44. [PMID: 24316311 DOI: 10.1016/j.chemphyslip.2013.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 11/13/2013] [Accepted: 11/14/2013] [Indexed: 02/06/2023]
Abstract
Lipid bilayer properties are quantified with a variety of arbitrary selected parameters such as molecular packing and dynamics, electrostatic potentials or permeability. In the paper we determined the effect of phloretin and 6-ketocholestanol (dipole potential modifying agents) on the membrane hydration and efficiency of the trans-membrane water flow. The dynamics of water molecules within the lipid bilayer interface was evaluated using solvent relaxation method, whereas the osmotically induced trans-membrane water flux was estimated with the stopped-flow method using the liposome shrinkage kinetics. The presence of phloretin or 6-ketocholestanol resulted in a change of both, the interfacial hydration level and osmotically driven water fluxes. Specifically, the presence of 6-ketocholestanol reduced the amount and mobility of water in the membrane interface. It also slows the osmotically induced water flow. The interfacial hydration change caused by phloretin was much smaller and the effect on osmotically induced water flow was opposite to that of 6-ketocholestanol.
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Vazdar M, Wernersson E, Khabiri M, Cwiklik L, Jurkiewicz P, Hof M, Mann E, Kolusheva S, Jelinek R, Jungwirth P. Aggregation of Oligoarginines at Phospholipid Membranes: Molecular Dynamics Simulations, Time-Dependent Fluorescence Shift, and Biomimetic Colorimetric Assays. J Phys Chem B 2013; 117:11530-40. [DOI: 10.1021/jp405451e] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Mario Vazdar
- Division
of Organic Chemistry and Biochemistry, Rudjer Bošković Institute, P.O.B.
180, HR-10002 Zagreb, Croatia
- Institute
of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
| | - Erik Wernersson
- Institute
of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
| | - Morteza Khabiri
- Institute
of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
| | - Lukasz Cwiklik
- Institute
of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- J. Heyrovský
Institute of Physical Chemistry, Academy of Sciences of the Czech Republic v.v.i., Dolejskova 3, 18223 Prague 8, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský
Institute of Physical Chemistry, Academy of Sciences of the Czech Republic v.v.i., Dolejskova 3, 18223 Prague 8, Czech Republic
| | - Martin Hof
- J. Heyrovský
Institute of Physical Chemistry, Academy of Sciences of the Czech Republic v.v.i., Dolejskova 3, 18223 Prague 8, Czech Republic
| | - Ella Mann
- Department
of Chemistry and the Ilse Katz Institute for Nanoscale Science and
Technology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Sofiya Kolusheva
- Department
of Chemistry and the Ilse Katz Institute for Nanoscale Science and
Technology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Raz Jelinek
- Department
of Chemistry and the Ilse Katz Institute for Nanoscale Science and
Technology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Pavel Jungwirth
- Institute
of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- Department
of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland
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Wallgren M, Beranova L, Pham QD, Linh K, Lidman M, Procek J, Cyprych K, Kinnunen PKJ, Hof M, Gröbner G. Impact of oxidized phospholipids on the structural and dynamic organization of phospholipid membranes: a combined DSC and solid state NMR study. Faraday Discuss 2013; 161:499-513; discussion 563-89. [PMID: 23805755 DOI: 10.1039/c2fd20089a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Membranes undergo severe changes under oxidative stress conditions due to the creation of oxidized phospholipid (OxPL) species, which possess molecular properties quite different from their parental lipid components. These OxPLs play crucial roles in various pathological disorders and their occurrence is involved in the onset of intrinsic apoptosis, a fundamental pathway in programmed mammalian cell death. However, the molecular mechanisms by which these lipids can exert their apoptotic action via their host membranes (e.g., altering membrane protein function) are poorly understood. Therefore, we studied the impact of OxPLs on the organization and biophysical properties of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) based lipid membranes by differential scanning calorimetry (DSC) and solid state nuclear magnetic resonance (NMR) spectroscopy. Incorporation of defined OxPLs with either a carboxyl group (1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PazePC)) or aldehyde (1-palmitoyl-(9'oxononanoyl)-sn-glycero-3-phosphocholine (PoxnoPC)) at their truncated sn-2-chain ends enabled us to reveal OxPL species-dependent differences. The calorimetric studies revealed significant effects of OxPLs on the thermotropic phase behavior of DMPC bilayers, especially at elevated levels where PazePC induced more pronounced effects than PoxnoPC. Temperature-dependent changes in the solid state 31P NMR spectra, which provided information of the lipid headgroup region in these mixed membrane systems, reflected this complex phase behavior. In the temperature region between 293 K (onset of the Lalpha-phase) and 298 K, two overlapping NMR spectra were visible which reflect the co-existence of two liquid-crystalline lamellar phases with presumably one reflecting OxPL-poor domains and the other OxPL-rich domains. Deconvolution of the DSC profiles also revealed these two partially overlapping thermal events. In addition, a third thermal, non-NMR-visible, event occurred at low temperatures, which can most likely be associated to a solid-phase mixing/demixing process of the OxPL-containing membranes. The observed phase transitions were moved to higher temperatures in the presence of heavy water due its condensing effect, where additional wideline 2H-NMR studies revealed a complex hydration pattern in the presence of OxPLs.
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Affiliation(s)
- Marcus Wallgren
- Department of Chemistry, Umeå University, Umeå, Sweden SE-901 87
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10
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Cholesterol Organization in Phosphatidylcholine Liposomes: A Surface Plasmon Resonance Study. MATERIALS 2012. [PMCID: PMC5448994 DOI: 10.3390/ma5112306] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Models for the organization of sterols into regular arrays within phospholipid bilayers have been proposed previously. The existence of such arrays in real systems has been supported by the fact that concentration-dependent sterol properties show discontinuities at the cholesterol mole fractions corresponding to regular lattice arrangements. Experimental results presented here are based on a surface plasmon resonance assay that was used to analyze rates of cyclodextrin-mediated removal of cholesterol from adsorbed liposomes at cholesterol mole fractions up to χC = 0.55. Two kinetic pools of cholesterol were detected; there was a fast pool present at χC > 0.25, and a slow pool, with a removal rate that was dependent on the initial χC but that did not vary as χC decreased during the course of one experiment. The cholesterol activity therefore seems to be affected by sample history as well as local concentration, which could be explained in terms of the formation of superlattices that are stable for relatively long times. We also describe a variation on the traditional lattice models, with phosphatidylcholine (PC) being treated as an arrangement of hexagonal tiles; the cholesterol is then introduced at any vertex point, without increasing the total area occupied by all the lipid molecules. This model is consistent with Langmuir trough measurements of total lipid area and provides a simple explanation for the maximum solubility of cholesterol in the PC bilayer.
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Franchino H, Stevens E, Nelson J, Bell TA, Bell JD. Wavelength dependence of patman equilibration dynamics in phosphatidylcholine bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:877-86. [PMID: 22954647 DOI: 10.1016/j.bbamem.2012.08.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 08/22/2012] [Accepted: 08/28/2012] [Indexed: 10/27/2022]
Abstract
Assessment of the equilibration kinetics of Patman at the edges of its emission spectra provided additional insights about membrane properties beyond those obtained from end-point fluorescence measurements. Upon introduction of the probe to aqueous suspensions of liposomes, the emission intensity slowly increased about 10-fold (t(½)=~100 s). The rate of equilibration depended on emission wavelength, and was usually faster at 500 than at 435 nm. However, this trend was reversed for equilibration with lipids at their phase transition temperature. The apparent rotational motion of the dye also differed between the long and short emission wavelengths but did not display the slow equilibration time dependence observed with intensity measurements. These results suggested that slow equilibration reflects relaxation of the immediate membrane microenvironment around the probe rather than slow insertion into the membrane. The data were rationalized with a model that allows two membrane/probe configurations with distinct microenvironments. The analysis suggests that by monitoring the equilibration pattern of Patman, inferences can be made regarding the polarity of two microenvironments occupied by the probe, the distribution of the probe among those microenvironments, and the kinetics with which they relax to equilibrium.
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Affiliation(s)
- Hannabeth Franchino
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
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12
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Vazdar M, Jurkiewicz P, Hof M, Jungwirth P, Cwiklik L. Behavior of 4-hydroxynonenal in phospholipid membranes. J Phys Chem B 2012; 116:6411-5. [PMID: 22577896 DOI: 10.1021/jp3044219] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Under conditions of oxidative stress, 4-hydroxy-2-nonenal (4-HNE) is commonly present in vivo. This highly reactive and cytotoxic compound is generated by oxidation of lipids in membranes and can be easily transferred from a membrane to both cytosol and the extracellular space. Employing time-dependent fluorescence shift (TDFS) method and molecular dynamics simulations, we found that 4-HNE is stabilized in the carbonyl region of a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer. 4-HNE is thus able to react with cell membrane proteins and lipids. Stabilization in the membrane is, however, moderate and a transfer of 4-HNE to either extra- or intracellular space occurs on a microsecond time scale. These molecular-level details of 4-HNE behavior in the lipid membrane rationalize the experimentally observed reactivity of 4-HNE with proteins inside and outside the cell. Furthermore, these results support the view that 4-HNE may play an active role in cell signaling pathways.
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Affiliation(s)
- Mario Vazdar
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, 16610 Prague 6, Czech Republic
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13
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Structure, dynamics, and hydration of POPC/POPS bilayers suspended in NaCl, KCl, and CsCl solutions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:609-16. [DOI: 10.1016/j.bbamem.2011.11.033] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 11/09/2011] [Accepted: 11/28/2011] [Indexed: 11/24/2022]
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Bagatolli LA. LAURDAN Fluorescence Properties in Membranes: A Journey from the Fluorometer to the Microscope. SPRINGER SERIES ON FLUORESCENCE 2012. [DOI: 10.1007/4243_2012_42] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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15
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Volinsky R, Cwiklik L, Jurkiewicz P, Hof M, Jungwirth P, Kinnunen PKJ. Oxidized phosphatidylcholines facilitate phospholipid flip-flop in liposomes. Biophys J 2011; 101:1376-84. [PMID: 21943418 DOI: 10.1016/j.bpj.2011.07.051] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 07/15/2011] [Accepted: 07/26/2011] [Indexed: 12/19/2022] Open
Abstract
Lipid asymmetry is a ubiquitous property of the lipid bilayers in cellular membranes and its maintenance and loss play important roles in cell physiology, such as blood coagulation and apoptosis. The resulting exposure of phosphatidylserine on the outer surface of the plasma membrane has been suggested to be caused by a specific membrane enzyme, scramblase, which catalyzes phospholipid flip-flop. Despite extensive research the role of scramblase(s) in apoptosis has remained elusive. Here, we show that phospholipid flip-flop is efficiently enhanced in liposomes by oxidatively modified phosphatidylcholines. A combination of fluorescence spectroscopy and molecular dynamics simulations reveal that the mechanistic basis for this property of oxidized phosphatidylcholines is due to major changes imposed by the oxidized phospholipids on the biophysical properties of lipid bilayers, resulting in a fast cross bilayer diffusion of membrane phospholipids and loss of lipid asymmetry, requiring no scramblase protein.
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Affiliation(s)
- Roman Volinsky
- Helsinki Biophysics and Biomembrane Group, Department of Biomedical Engineering and Computational Science, Aalto University, Espoo, Finland
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Olżyńska A, Jurkiewicz P, Hof M. Properties of Mixed Cationic Membranes studied by Fluorescence Solvent Relaxation. J Fluoresc 2008; 18:925-8. [DOI: 10.1007/s10895-008-0321-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Accepted: 01/21/2008] [Indexed: 10/22/2022]
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